Various classes of dyes have long been known that reversibly change their color when irradiated with light of certain wavelengths, particularly sunlight. This is due to the fact that these dye molecules are converted by light energy into an excited state, which they leave again when the energy input is interrupted and they return to their ground state. These photochromic dyes include various pyran systems, which have previously been described in the prior art, having different base systems and substituents.
Pyrans, especially naphthopyrans and larger ring systems derived from these, are currently the most commonly used class of photochromic compounds. Although patented for the first time back in 1966 (U.S. Pat. No. 3,567,605), two pyran compound classes were first developed in the 1990s which are suitable for use in phototropic spectacle lenses. The latter concerns 2,2-diaryl-2H-naphtho[1,2-b]pyrans and 3,3-diaryl-3H-naphtho[2,1-b]pyrans, whose open (excited) forms have various darkening colors from yellow to red-violet.
2,2-Diaryl-2H-naphtho[1,2-b]pyrans having an additional fused attachment on the pyrano-fused benzene ring are of considerable interest, since they absorb longer wavelengths due to their larger ring systems and thus violet and blue darkening colors are accessible. This additional fused attachment is generally a benzene ring (in formula (I) the benzene ring having the substituents R2), which is again bridged in the ortho position to the naphthopyran (see Z in formula (I)).
If this bridge constitutes only one atom, this results in a 5-membered ring fused to the benzopyran. Examples for one carbon atom can be found in U.S. Pat. Nos. 5,645,767, 5,723,072 and 5,955,520 and for one oxygen atom in U.S. Pat. No. 6,018,059.
In U.S. Pat. No. 5,723,072, in addition to this base system, an un-, mono- or disubstituted heterocyclic ring may be fused to the g, h, i, n, o or p side of the indenonaphthopyran. Thus indeno[1,2-f]naphtho[1,2-b]pyrans having a very wide range of possible substituents are disclosed.
WO 96/14596, WO 99/15518, U.S. Pat. No. 5,645,767, WO 98/32037 and U.S. Pat. No. 5,698,141 disclose photochromic indeno-fused naphthopyran dyes derived from 2H-naphtho[1,2-b]pyran, the compositions containing them and a method for the preparation thereof. In U.S. Pat. No. 5,698,141, in addition to this base system, an un-, mono- or disubstituted heterocyclic ring may be fused to the g, h, i, n, o or p side of the indenonaphthopyran. The respective very extensive substituent list also comprises very particular spiro compounds, namely those systems having a spiro heterocyclic group, wherein, including the spiro atom at the 13-position of the base system, a 5- to 8-membered ring is present which always comprises two oxygen atoms. A further embodiment of the spiro ring is found in the Japanese application 344762/2000.
The different photochromic dyes available in the prior art have disadvantages, however, which substantially affect the wear comfort of the spectacles wearer when using sun protection lenses. Firstly, the dyes do not have a sufficiently long-wave absorption in the excited state and in the non-excited state. Secondly, there is often too high a temperature sensitivity of the darkening, and at the same time too slow a brightening can occur. Moreover, the dyes available in the prior art often have an insufficient lifetime and therefore allow only a low service life of the sun protection lenses. The latter manifests itself in rapidly declining performance and/or noticeable yellowing.
The substituents in the position ortho to the pyran oxygen atom are mainly referred to in the prior art only with B and B′. They are mainly aromatic or heteroaromatic substituents. In addition, the substituents B and B′—together form a separate cyclic aliphatic or aromatic or heteroaromatic ring system. Influencing the photochromic properties by suitable selection of the substituents B and B′ with the exception of ortho substituents on the benzene ring adjacent to the pyran oxygen is virtually unreported in the prior art. Even small ortho substituents on the benzene ring adjacent to the pyran oxygen, such as fluorine, methyl or methoxy, slow the brightening rate so severely that they cannot be used as intended in spectacle lenses.
It is an object of the present invention to provide a class of novel photochromic compounds having improved properties compared to the structures described in the prior art. These include, inter alia, a very high darkening performance even at elevated temperatures, a rapid brightening rate and a very good light stability.
This problem is solved by the subjects characterized in the claims.
In particular, photochromic naphthopyrans are provided having the general formulae (I) and (II):
wherein    the radicals R1 and R2 are each independently a substituent selected from the group α, consisting of a hydrogen atom, a (C1-C6)-alkyl radical, a (C1-C6)-thioalkyl radical, a (C3-C7)-cycloalkyl radical which may have one or more heteroatoms such as O or S, a (C1-C6)-alkoxy radical, an hydroxyl group, a trifluoromethyl group, bromine, chlorine, fluorine, an unsubstituted, monosubstituted or disubstituted phenyl, phenoxy, benzyl, benzyloxy, naphthyl or naphthoxy radical, wherein the substituents in turn may be selected from the group α; or    two radicals R1 and/or two radicals R2 each independently form an unsubstituted, monosubstituted or disubstituted benzo, pyrido, benzofuro or benzothieno ring fused to the base structure, the substituents of which may be selected from the group α; Z is selected from —CR10R11—, —O—, —S—, —NPh-, —N(C1-C6)alkyl, —O—CR10R11—, —CR10R11—O—, —S—CR10R11—, —CR10R11—S—, —CR10R11—CR10R11—, —CR10═N— or —CR10═CR11—, where the substituents R10 and R11 may be selected from the group α, preferably from a hydrogen atom, a (C1-C6)-alkyl radical, a (C3-C7)-cycloalkyl radical, an un-, mono- or disubstituted phenyl, benzyl or naphthyl radical;    or Z, incorporating the spiro-carbon atom, is a 3- to 8-membered carbomonocyclic or heteromonocyclic ring which may optionally bear one or more substituents from the group α, and to which one to three aromatic or heteroaromatic ring systems may be fused, wherein the ring system(s) are independently selected from the group β consisting of benzene, naphthalene, phenanthrene, pyridine, quinoline, furan, thiophene, pyrrole, benzofuran, benzothiophene, indole and carbazole, which in turn may be substituted with one or more substituents selected from the group α;    or Z, incorporating the spiro-carbon atom, is a 7- to 12-membered carbobicyclic ring or a 7- to 12-membered carbotricyclic ring, which in turn may have one, two, three or four substituents selected from the group α,    and wherein    B is selected from one of the following groups a) or b), wherein    a) is a mono-, di- and trisubstituted aryl radical, wherein the aryl radical is phenyl, naphthyl or phenanthryl;    b) is an un-, mono- and disubstituted heteroaryl radical, wherein the heteroaryl radical is pyridyl, furanyl, thienyl, benzofuranyl, benzothienyl, 1,2,3,4-tetrahydrocarbazolyl and julolidinyl;    wherein the substituents of the aryl and heteroaryl radicals in a) and b) are those selected from the group α or the group χ consisting of hydroxy, amino, mono-(C1 C6)-alkylamino, di-(C1-C6)-alkylamino, and on the phenyl ring un-, mono- or disubstituted phenethenyl, un-, mono- or disubstituted (phenylimino)methylene, un-, mono- or disubstituted (phenylmethylene)imino and un-, mono- or disubstituted mono- and diphenylamino, piperidinyl, N-substituted piperazinyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, indolinyl, morpholinyl, 2,6-dimethylmorpholinyl, thiomorpholinyl, azacycloheptyl, azacyclooctyl, un-, mono- or disubstituted phenothiazinyl, un-, mono- or disubstituted phenoxazinyl, un-, mono- or disubstituted 1,2,3,4-tetrahydroquinolinyl, un-, mono- or disubstituted 2,3-dihydro-1,4-benzoxazinyl, un-, mono- or disubstituted 1,2,3,4-tetrahydroisoquinolinyl, un-, mono- or disubstituted phenazinyl, un-, mono- or disubstituted carbazolyl, un-, mono- or disubstituted 1,2,3,4-tetrahydrocarbazolyl and un-, mono- or disubstituted 10,11-dihydrodibenz[b,f]azepinyl, wherein the substituent(s) in turn may each independently be selected from (C1 C6)-alkyl, (C1-C6)-alkoxy, bromine, chlorine or fluorine;    or wherein two directly adjacent substituents of the aryl and heteroaryl radicals in a) and b) are a V—(CR12R13)p—W moiety, where p is 1, 2 or 3, R12 and R13 may be hydrogen, methyl or phenyl and V and W may independently be oxygen, sulfur, N—(C1-C6)-alkyl, N—C6H5, CH2, C(CH3)2 or C(C6H5)2, wherein two or more adjacent carbon atoms in this V—(CR12R13)p—W moiety each independently can also be part of a fused benzo ring system, which in turn may have one or more substituents selected from the group α or the group χ;    and wherein the aryl radical or heteroaryl radical of the group B in the two positions ortho to the point of attachment to the pyran ring has no substituent other than hydrogen,    and wherein C is a substituent of the following structure,
wherein R9 is defined as R1 and R2, where m, n and o are independently an integer from 1 to 4;    wherein R3 to R8 are each independently a substituent selected from the group α; or    R3 together with R4 or R5 together with R6 or R7 together with R8 independently form, with the respective common carbon atom, a 3- to 8-membered carbomonocyclic or heteromonocyclic ring, which optionally bears one or more substituents from the group α, and to which one to three aromatic or heteroaromatic ring systems may be fused, wherein the ring system(s) are independently selected from the group β consisting of benzene, naphthalene, phenanthrene, pyridine, quinoline, furan, thiophene, pyrrole, benzofuran, benzothiophene, indole and carbazole, which in turn may be substituted with one or more substituents selected from the group α; or four adjacent radicals R3 to R6 or R5 to R8 form an un-, mono- or disubstituted benzo or pyrido ring, fused to the base structure, the substituents of which may be selected from the group α;    where X is N or CR14, wherein R14 is selected from the group consisting of hydrogen, a (C1-C6)-alkyl radical and un-, mono- and disubstituted phenyl, the substituents of which are selected from the group α; and    where Y is O, S, NR15, CR15R16 or CR15R16—CR15R16, wherein R15 and R16 may each be selected as R14, or the two radicals R15 and R16, together with the common carbon atom, form a 3- to 8-membered carbomonocyclic or heteromonocyclic ring, which optionally bears one or more substituents from the group α, and to which one to three aromatic or heteroaromatic ring systems may be fused, wherein the ring system(s) are independently selected from the group β consisting of benzene, naphthalene, phenanthrene, pyridine, quinoline, furan, thiophene, pyrrole, benzofuran, benzothiophene, indole and carbazole, which in turn may be substituted with one or more substituents selected from the group α.
The photochromic fused naphthopyrans are characterized by a benzene ring which is adjacent to the pyran and is linked to the para substituent via both meta positions. The compounds according to the invention are characterized by very high darkening performance even at elevated temperatures, rapid brightening rates and also very good light stabilities. The photochromic fused naphthopyrans according to the invention preferably have the general formula (I) above.
Particularly preferred photochromic fused naphthopyrans according to the present invention, having a benzene ring which is adjacent to the pyran oxygen and is linked to the para substituent via both meta positions, have the following general formulae (III), (IV) and (V):
wherein all radicals are as defined above and wherein the spiro-ring in formula (III), incorporating the spiro-carbon atom, is a 5- to 8-membered carbocyclic ring, which optionally bears one or more substituents from the group α, and to which one to three benzene rings may be fused, which in turn may be substituted with one or more substituents selected from the group α.
In a preferred embodiment of the present invention, the radical B is selected from the group a). In a further embodiment, X is preferably N in the radical C. In the radical C, Y is preferably CR15R16 or CR15R16—CR15R16, wherein R15 and R16 are as defined previously and are preferably selected from the group consisting of hydrogen, a (C1-C6)-alkyl radical and un-, mono- and disubstituted phenyl, the substituents of which are selected from the group α. The radicals R3 to R8 are preferably each independently a substituent selected from the group α.
In an embodiment of the present invention, the radicals R3 and R4 are each independently a substituent selected from the group α, and the four radicals R5 to R8 together are an un-, mono- or disubstituted benzo or pyrido ring, fused to the base structure, the substituents of which may be selected from the group α
In a particularly preferred embodiment, the radical C has the following structures:

Furthermore, in a further embodiment, two radicals R2 in the above formulae (I)-(V) form an un-, mono- or disubstituted benzo, pyrido, benzofuro or benzothieno ring fused to the base structure, the substituents of which may be selected from the group α. Two radicals R2, mutually in the ortho position, present in the above formulae (I)-(V) are particularly preferably a benzofuro fused attachment.
Z is preferably selected from —CR10R11—, —O—CR10R11—, —CR10R11—O—, —CR10R11—CR10R11 or —CR10═CR11—, wherein the substituents R10 and R11 are selected from the group α, preferably from a hydrogen atom, a (C1-C6)-alkyl radical, a (C3-C7)-cycloalkyl radical, an un-, mono- or disubstituted phenyl, benzyl or naphthyl radical.